public class Ex5_25{
	public static void main(String[] args){
		System.out.printf("%s\n", convertMillis(555550000));
	}

	public static String convertMillis(long millis){
		long totalSeconds = millis / 1000;
		long seconds = totalSeconds % 60;
		long totalMinutes = totalSeconds / 60;
		long minutes = totalMinutes % 60;
		long hours = totalMinutes / 60;
		return hours + ":" + minutes + ":" + seconds;
	}
}